Locking electrical connector



July 16, 1968 H. HUBBELL 3,393,395

LOCKING ELECTRICAL CONNECTOR Filed Dec. 22, 1965 2 Sheets-Sheet l I I 45 I INVENTOR.

a5 MW July 16, 1968 Filed Dec. 22, 1965 H. HUBBELL 3,393,395

LOCKING ELECTRICAL CONNECTOR 2 Sheets-Sheet 2 92 1911 156 154 #fi- 172 175 151i 135 A 176 j i mm. m l C 174 I,

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United States Patent 3,393,395 LOCKING ELECTRICAL CONNECTOR Harvey Hubbell, Southport, Conn., assignor to Harvey Hubbell, Incorporated, Bridgeport, Conn., 21 corporation of Connecticut Filed Dec. 22, 1965, Ser. No. 515,596 3 Claims. (Cl. 339-91) ABSTRACT OF THE DISCLOSURE A rotatably locking electrical connector with a positive lock. The receptacle body, in addition to the usual arcuate slots, includes a locking recess. The detachable cap, in addition to the usual cont-act blades, includes a spring load locking pin. The locking pin is positioned to enter the recess when the body and cap are fully mated. In order to disengage the cap from the body, the locking pin must be withdrawn from the recess against the force of the spring.

This invention relates to a locking electrical connector and, more particularly, to a connector of the type wherein the electrical connection is made by rotating a separable cap relative to a receptacle body.

Rotatably locking separable electrical connectors are well known in the wiring art. In a connector of this type, the end face of the receptacle body defines a plurality of arcuate slots which are arranged about a common center and communicate with internally formed chambers enclosing the female contacts. The separable cap portion of the connector carries a plurality of longitudinally extending L-shaped blades which are also positioned about a common center. To mate the cap and receptacle, the blades are inserted into the slots and into the corresponding female contacts. The cap is then rotated in a clockwise direction, the blades remaining within the female contacts. The circumferentially extending portions of the L-shaped blades are then misaligned with the slots and extend behind the receptacle end face. It is then impossible to separate the cap from the receptacle by a direct axial pull. To separate the two members, the cap must be rotated counterclockwise relative to the receptacle body to realign the blades and slots before withdrawal.

Although rotatably locking electrical connectors are widely and successfully used through the electrical industry it would be desirable to provide a connector having even more positive locking means. This i particularly true where the connectors are used in certain industrial applications where they may be subjected to considerable vibration. It is possible, under such circumstances, for the cap to be vibrated counter-clockwise relative to the receptacle so that they become unlocked from one another.

Accordingly, it is a primary object of the present invention to provide a rotatably locking electrical connector having positive supplemental locking means. Other objects are to provide such a connector wherein the supplemental locking means does not interfere with normal operation of the connector and to provide such a connector which will not separate accidentally under vibration and similar conditions.

The manner in which the foregoing objects are achieved will be more apparent from the following description, the appended claims and the figures of the attached drawings, wherein:

FIG. 1 is a front view of a connector cap and recep tacle body in accordance with this invention, shown in their separated condition;

FIG. 2 is a front view of the cap and receptacle of FIG. 1, shown in their interconnected condition, portions thereof being broken away to illustrate their internal construction;

FIG. 3 is a cross section taken along the line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 2 showing the supplemental locking means withdrawn prior to separation of the cap and receptacle body;

FIG. 5 is a top view of the cap of FIG. 4;

FIG. 6 is a cross section of a cap showing a modified form of the supplemental locking feature;

FIG. 7 is a front view of another modification of a locking connector cap and receptacle body, portions thereof being broken away to illustrate the internal construction;

FIG. 8 is a cross section taken along the line 88 of FIG. 7;

FIG. 9 is a view similar to FIG. 7, showing the supplemental locking means partially withdrawn prior to separation of the cap from the receptacle body;

FIG. 10 is a top view of another modification of a locking connector cap;

FIG. 11 is a front view of the cap of FIG. 10, inserted in a receptacle body;

FIG. 12 is an enlarged cross section taken substantially along the line 12-12 of FIG. 11;

FIG. 13 is a top view of another modification of a locking connector cap;

FIG. 14 is a front view of the cap of FIG. 13 inserted in a receptacle body;

FIG. 15 is an enlarged cross section taken substantially along the line 15-15 of FIG. 14;

FIG. 16 is a partial top view of another modification of a locking connector cap;

FIG. 17 is a front view of the cap of FIG. 16 inserted in a receptacle body, portions of the cap and receptacle being broken away to illustrate the internal construction;

FIG. 18 is a partial top view of another modification of a locking connector cap; and

FIG. 19 is a front view of the cap of FIG. 18 inserted in a receptacle body, portions of the cap and receptacle being broken away to illustrate the internal construction.

The objects of this invention are achieved by means of a locking electrical connector comprising an insulating receptacle body and a detachable cap. The receptacle body defines a plurality of chambers and a plurality of arcuate slots, one slot communicating with each of the chambers. A locking recess is also provided in the receptacle body. Each chamber encloses a stationary electrical contact. The detachable cap includes a plurality of elongated contact blades for selective insertion into and through the slots to engage the stationary contacts by longitudinal movement of the cap toward the receptacle. The slots have an arcuate length suflicient to permit movement of the contact blades in the slots upon relative rotation of the cap against the body to a locking position. A retractable locking pin is provided on the cap and is positioned to enter the locking recess upon rotation of the cap to its locking position.

With particular reference to FIGS. 1-4 there is illustrated a connector including a receptacle body 10 of insulating material and a detachable cap 12. As many of the features of this connector are conventional, they will not be illustrated in detail. The receptacle body is secured to a power supply cable 14 by means of a cable clamp 16 and the cap is secured to a load cable 18 by means of a cable clamp 20. The disclosed embodiment of the invention includes a cap of the three-bladed type having two line blades and a grounded neutral blade. Thus, the receptacle body 10 defines three internal chambers 22, only one of which is shown in FIGS. 2 and 4. Each chamber encloses a female contact. The grounded neutral contact 24 is illustrated. The receptacle body includes an outer end face 25 which defines a plurality of slots communicating with the inner chambers. Each of slots 26, 28 communicates with a chamber containing a. line contact and slot 30 communicates with the chamber 22 containing grounded neutral contact 24. All three slots are concentrically positioned in end face 25, the line slots 26, 28 being positioned on one radius and the grounded neutral slot 30 being positioned on a shorter radius. The grounded neutral slot 30 also includes a radially extending keyway 32. The slot configuration so far described is commonly used on prior art devices. One distinguishing feature of this invention, however, is that grounded neutral slot 30 is formed with an additional, partially circular, recess 34 which extends partially into the receptacle body from its end face 25.

The cap 12 which is used with the receptacle body 10 includes a disc-shaped body 36 of insulating material. Extending from a recessed end face 38 (FIG. 4) of body 36 are a plurality of elongated L-shaped arcuate blades including line blades 40, 42 and a grounded neutral blade 44. The blades are positioned so as to enter the slots 26, 28, 30 and grounded neutral blade 44 also includes a radial lug 46 for insertion in the keyway 32. The electrical connections to the blades are conventional and are not illustrated.

The locking mechanism of the invention includes a disc 48 mounted against the rear surface of the cap body 36 and defining a central aperture 50 surrounding the cable clamp and cable 18. The disc 48 is mounted for axial longitudinal displacement from the cap body-36. This is accomplished by mounting the disc 48 against the body 36 by means of three screws 52. Each of the screws extends through a passageway 54 in disc 48 and its lower end is firmly embedded in the body 36. Each of passageways 54 is countersunk at its upper end 56 to receive a compression coil spring 58 which is mounted on each screw between its head and the countersunk portion. It will thus be seen that disc 48 is normally biased against body 36, but is liftable axially against the force exerted by the springs 58, as shown in FIG. 4. A locking pin 60 is rigidly mounted in disc 48 and extends through a guideway 62 in cap body 36 to extend from the end face 38 adjacent the grounded neutral blade 44.

It is believed that the operation of the invention shown by FIGS. 1-4 will now be apparent to those skilled in the art. In order to interconnect the detachable cap 12 with the receptacle body 10, the two elements are advanced together in the usual fashion, the body 36 being grasped by the fingers of one hand. Upon the initial insertion of the blades into the slotsfthe locking pin 60 will not be aligned with the recess 34 in slot 30. Accordingly, the end of the locking pin will bear against the end face of the receptacle body 10, forcing the locking pin upward within the guideway 62 and driving the disc 48 away from the body 36 against the force of coil springs 58. Upon clockwise rotation of the cap 12 into its normal locking position, the locking pin 60 will become aligned with the recess 34 and drop into position therein, as shown in FIGS. 2 and 3. The locking pin 60 then serves to prevent any inadvertent rotation of the cap relative to the receptacle body, such as might be induced by vibration.

In order to disconnect the cap from the receptacle body, the disc 48 is grasped by the fingers and withdrawn, as shown in FIG. 4. This retracts the end of locking pin 60 from the recess 34 and above end face 25 and the disc 48 may thenbe rotated counterclockwise. The cap body 36 will also be rotated counterclockwise, releasing the blades and allowing the cap to be withdrawn.

Various modifications of this invention will be immediately apparent to those skilled in the art. One such modification is illustrated in FIG. 6. This arrangement is very similar to that of FIGS. 1-5, with the exception that a modified locking pin 64 is employed which is not firmly fixed in the disc 48'. Rather, the pin is axially slidable within an opening 66 in the disc, but is biased to its downward position by means of a spring 68 compressed between the disc 48' and a shoulder 70 on the pin. The advantage of this modification is that the fingers may grasp the disc 48 during both connection and separation of the cap and receptacle body. Upon connection, the locking pin 64 will bear against the end face 25 and will be forced upwardly into the position indicated by the dotted lines. This will permit the cap to be rotated until the pin 64 seats within recess 34 under the influence of spring 68. Upon withdrawal, the disc 48' will be displaced as previously explained, lifting the enlarged head of the locking pin 64 to the dotted line position to release its lower end from engagement in recess 34.

Another modification is shown in FIGS. 7-9. In this modification, the cap body 72 is quite similar to the cap body 36 of FIGS. 1-5, but without the disc. The locking pin 74 has an upper end 76 of circular cross section axially slidable within a passageway 78 in the cap body. The lower end of the locking pin 74 is substantially U- shaped and includes a pair of spaced ribs 80 defining a groove therebetween which engages the edge of grounded neutral blade 44". A portion of the passageway 78 is enlarged and encloses a coil spring 82 which biases the locking pin 74 downwardly. The corresponding receptacle body 84 for use with this form of invention defines an enlarged grounding slot 86 for receiving the lower end of the locking pin and, at the base of the slot, a locking recess 88 is formed. The interlocked position of the parts is shown in FIG. 7, the lower end of the locking pin 74 being seated within the recess 88. In order to separate the cap from the receptacle body, the head of the locking pin 74 is grasped and raised, as shown in FIG. 9. This lifts the bottom end of the locking pin out of the locking recess 88 and permits the cap to be rotated counterclockwise, releasing the locking blades.

In the modification of FIGS. 10-12, the connector cap 90 is provided with a metal shell 92 which encloses an insulating inner disc 94 and an insulating outer disc 96. Discs 94 and 96 form the body of the connector cap and define a cylindrical cavity 98 which extends downwardly from the top surface of the disc 94. A narrow slot 100 extends through the sides of the discs 94 and 96 to cavity 98. A slot 101, which is aligned with slot 100, extends through shell 92. Disc 96 further includes a cylindrical passageway 102 having a smaller diameter than the cavity 98 which extends from the cavity to the end face of the connector cap. The shell 92 includes an opening 104 which is axially aligned with the cavity 98 and the passageway 102. The end face of the receptacle body 106 defines a cylindrical recess 108 which is aligned with the passageway 102 when the connector cap and the receptacle body are in the interlocking relationship. Externally mounted on the shell 92 is an L-shaped thumb latch 110 which is normally positioned against the surface of the metal shell 92 as shown in FIG. 12. The shorter leg of the L-shaped thumb latch extends across the metal shell at the rearward end surface of the connector cap 90 and the longer leg extends down the side of the shell, substantially covering slot 101. A latching pin 112 is slidably positioned within the opening 104, cavity 98 and passageway 102 and is secured at its rearward end to the thumb latch 110. Secured to the longer leg of the thumb latch 110 is one end of an actuating pin 114 which extends through slots 101, 100 and terminates at its inner end in a circular ring 116 which encircles latching pin 112 and is slidable within cavity 98. A coil spring 118 is mounted within cavity 98 encircling the pin 112 and extends from the shell 92 to the ring 116. Spring 118 exerts force against the ring 116 which normally retains the thumb latch 110 and the latching pin 112 in their forward positions as illustrated in FIG. 12.

To disconnect connector cap 90 from receptacle body 106, it is merely necessary to grasp the connector cap,

placing the thumb on thumb latch 110 and retracting it against the force of spring 118. The thumb latch slides rearwardly on the shell, retracting the latching pin 112 from engagement with the recess 108, permitting rotational unlocking movement of the connector cap relative to the receptacle body. On mating the cap with the receptacle, the thumb latch and latching pin are automatically retracted by the end of the latching pin 112 bearing against the end face of the receptacle body 106.

FIGS. 13-15 illustrate a construction which is similar in principle to that of the modification of FIGS. -12. However, the construction is simplified by employing a differently shaped thumb latch 120 which also performs the function of the locking pin. This is achieved, as shown in FIG. 15, by forming the thumb latch into what is basically a U-shaped including an outer leg 122 which extends over the end of shell 124 and an inner leg 126 parallel thereto which extends into a chamber 128 formed in the connector cap 130 through a slot 132 in shell 124. The end of the inner leg 126 is bent forwardly to provide a latching blade 134 which extends through a slot 136 in the connector cap to engage a recess 138 in the receptacle body 140. The two legs of the thumb latch are joined by a guide pin 142. A spring 144 encircles the guide pin and extends from the inner leg 126 to the shell 124. It will now be apparent that the latching blade of this modification is actuated in the same manner as the locking pin of the modification of FIGS. 1012 by merely retracting the thumb latch 120, causing the blade 134 to be retracted from recess 138.

In the modification of FIGS. 16 and 17 there is illustrated a connected cap 146 and a receptacle body 148 which are also locked by means of a latching pin 150 which extends through the connector cap into a locking recess 152 in the receptacle body lined with a metallic bushing 153. In this modification, the passageway within the cap is also provided with a metallic bushing 154 and the latching pin 150 has an enlarged head 157 at its rearward end and an enlarged collar 156 which slides within the bushing. A spring 158 is mounted between the metal shell 160 of the cap and the collar 156 and tends to retain the latching pin in its advanced position. The pin is retracted by means of a thumb lever 162 which is pivotally mounted by means of a pivot pin 164 extending between two spaced lugs 166a, 166b on the shell 160. One end 168 of the thumb lever is normally positioned against the shell 160 and includes an opening through which the latching pin 150 extends, the enlarged head 157 of the latching pin resting upon the end 168. The opposite end 170 of the thumb lever is spaced from the shell 160 so that it may be readily depressed. In order to retract the latch ing pin 150 in this modification, it is merely necessary to depress the end 170 of thumb lever 162, causing it to pivot on pivot pin 164 and retract the head 157 of latching pin 150, thereby withdrawing it from its position within the recess 152.

In the modification of FIGS. 18 and 19, the connector cap 172 and receptacle body 174 are locked by means of a latching pin 176 which extends through a passageway in the connector cap having a rearward portion 178 of greater diameter than its forward portion 180, thereby forming an annular ledge 182. In this arrangement, the latching pin 176 carries a collar 184 which is positioned intermediate the ledge 182 and the metal shell 186 of the connector cap. A coil spring 188 encircles the latching pin 176 between ledge 182 and collar 184. This spring is normally compressed when the latching pin is in its forward position, as shown in FIG. 19 so that it tends to retract the pin to the position indicated by the broken line, thus extracting it from the locking recess 190 in the receptacle body 174. The rearward end of the latching pin 176 terminates in an enlarged head 192. This head is fixedly secured to a latching plate 194. Latching plate 194 includes a U-shaped recess 196 which permits it to be pivoted beneath the head 198 of a lock pin projecting from the metal shell 186. It will thus be seen that, in this arrangement, the operation is slightly difierent from the preceding modifications in that the latching pin 176 is normally urged by spring 188 out of engagement with the recess 190 in the receptacle body 174. The parts are mated with latching plate 194 pivoted to the position illustrated by the broken lines in FIG. 18, which allows the spring to retract the latching pin. After the parts are mated, they are locked by depressing the latching plate 194, which forces the latching pin 176 into the recess 190. The latching plate is then pivoted into the position shown by solid lines in FIG. 18 where it is secured by the head 198 of the lock pin.

It is believed that the many advantages of this invention will be fully apparent to those skilled in the art. It is also believed that those skilled in the art will understand that a number of variations and modifications may be made in the invention without departing from its spirit and scope. Accordingly, the foregoing description is intended to be illustrative only, rather than limiting. This invention is limited only by the scope of the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A locking electrical connector comprising: an insulating receptacle body defining therein a plurality of chambers, a plurality of arcuate slots, one slot communicating with each of said chambers, and a locking recess; a stationary contact in each of said chambers; a detachable cap body having a plurality of elongated contact blades for selective insertion into and through said slots to en gage said stationary contacts by relative longitudinal movement of said cap toward said receptacle body, said slots being of an arcuate length to permit movement of said contact blades in said slots upon relative rotation of said cap against said body to a locking position; a springloaded disc on said cap axially movable relative thereto; and a locking pin carried by said disc normally biased into engagement with said recess.

2. The connector of claim 1 wherein said locking pin is fixedly secured to said disc.

3. The connector of claim 1 wherein said locking pin is axially movable relative to said disc.

References Cited UNITED STATES PATENTS 1,776,280 9/1930 Boyd 28591 2,684,860 7/ 1954 Rafferty. 2,968,017 l/l961 Healy 339-189 3,226,667 12/1965 Senior 339-91 MARVIN A. CHAMPION, Primary Examiner. JOSEPH H. MCGLYNN, Assistant Examiner. 

